Watchman s time-detector



UNITED STATES PATENT OFFICE.

GEORGE B. FESSENDEN, OF BOSTON, MASSACHUSETTS.

WATCH MANS TIM E-DETECTO R.

SPECIFICATION forming part of Letters Patent No. 381,992, dated May 1,1888.

Application filed June 26, 1884.

To all whom it may concern:

Be it known that I, GEORGE B. FESSENDEN, of Boston, county of Suffolk,State of Massachusetts, have invented an Improvement in 5 WatchmensTime-Detectors, of which the following description, in connection withthe accompanying drawings, is a specification, like letters on thedrawings representing like parts.

My invention relates to a watchmans detector of that class in which thewatchman visits a numberof stations and by means of electric connectionsbetween the stations and a receiving apparatus causes a record to bemade of the fact that the stations have been visited, which record alsoshows the time at which the round of visits was made.

' In apparatus of this class as heretofore generally made the clock orrecording apparatus is connected with the different stations by a seriesof normally-open circuits having a com mon return-wire containing abattery or other source of electricity, so that when the proper branchis closed by a suitable key or button at any station a current will becaused to flow, which, through suitable electromagnetic devices at theclock, causes a record to be made on a traveling recording-surfacehavinga uniform time movement. The record-mark on the traveling surfacehas usually been made by the direct action of an electro-magnet or itsretractor, thus requiring a sufficientlystrong current to do the work ofmaking the record, which is usually made by pricking or punching a holethrough the traveling surface, which is usually a sheet of paper.

The object of my invention is to remove certain objections existing inthe class of apparatus described; and the invention consists partly inhaving the source of the electric current located at the stations,instead of in the common return-wire, and thus removing the possibilityof producing a record by connecting a branch wire with the return-Wireat any other point except at the station to be visited.

The invention also consists in employing mechanical electric generatorsinstead of batteries in the branch circuits, thus insuring severalimportant advantages and especially increasing the difficulty oftampering with the apparatus or producing the record in any other mannerthan that intended.

Figure 1 represents a magneto-generator Serial No. 136,055. (No model.)

such as employed at the stations to be visited for the purpose ofgenerating the current that affects apparatus at the receivingstation,so as to cause a record to be made at the proper time. Fig. 2 is a frontelevation of a portion of the receiving apparatus called thetransmitter, the said transmitter having its operation controlled by thecurrents generated at the stations and itself controlling the operationof the recording apparatus by which the record of the watchmans visitsis made, the said recording mechanism being indicated by diagram in Fig.2. Fig. 3 is a diagram representing a series of stations and thecircuits connecting the same with the transmitter represented in Fig. 2,and Figs. 4 and 5 sectional details on broken lines w and y of Fig. 2.

The invention is shown as embodied in an apparatus substantially likethat shown and described in Letters Patent No.236, 257 ,granted to E. T.Quimby, to which reference may be had. The said apparatus comprises acircuitchanger, (represented in Fig.2,) which is connected with andcontrolled by the circuits from the different stations to be visited,and also controls the said circuits, placing one station in circuitafter another, and the said instrument also controls the operation ofthe recording device m, Fig. 2, and thus acts as a transmitter, by whichthe watchman operating at the stations causes a signal to be transmittedto the recorder. The said transmitter consists of a mechanical motor ortrain of wheel-work, d, controlled by a detent or stopshoulder, a, onthe armature e of the electromagnet e, the said train of wheehworkoperating an arm, f, having a yielding projection, f, that moves overthe inner surface of an insulating-ring, f, provided with a series ofmetallic pins or studs, f connected with wires 9, leading to thedifferent stations to be visited.

The train of wheel-work cl and the stop projections d,controlled by thedetent-shoulder e, are so proportioned and arranged that each time thesaid train is released it will move far enough to carry the arm f fromone to the next of the studs f ()ne terminal of the magnet e isconnected with ,a wire, 9, that leads to all the stations (numbered 1 23, &c., in Fig. 2,) and thus forms a common rcturnwire for all thebranch circuits 9 leading to the said stations, and the other terminalof said magnet is connected by wire g with the framework of thetransmitter, which is in electrical connection with the arm f andcontact-point f thereof. Thus,when the said contact-point f rests uponone of the projections f, as shown, the station connected with thebranch wireg leading from that particular projection f is in circuit andall the other stations are in open circuit at the ringf If, now, acurrent is transmitted from a station that is in circuit,the magnet 6will be energized, the motor (I released, and the armf will move on tothe next stud, thus placing the station at which it was just operated inopen circuit and closing the circuit to the next station of the series.It is therefore necessary in order to produce complete operation thatthe watchman should visit all the stations in regular order.

The construction and mode of operation of the transmitter as thus fardescribed are substantially the same as in the Quimby patent beforereferred to and form no part of the present invention. In the saidQuimby patent, however, and in all other watchmans de tector apparatusso far as I know, the magnet e, that is operated from the stations,hasbeen energized by the current of the battery or source of electricityplaced in the wire g,that leads to all the stations, and consequently ifa cross-connection should be made between the branch wire 9 leading to agiven station and the battery-wire g, as indicated at 9*, Fig. 3, themagnet e would be affected just the same as if the watchman had visitedthe corresponding station.

The present invention consists, mainly,in removing the source ofelectricity from the wire leading to all the stations, and placing agenerator or source of electricity at each station, so that it makesconnection or forms a part of the connection between the branch wire 9lead ing to that station and the common returnwire, 9'. By thisarrangement a cross-connection between the station-wire g and returnwire such as represented at 9, Fig. 3, will produce no effect on themagnet e of the receiving apparatus. I have found that in thisarrangement,in which the source of electricity is placed at the stationsor in the station-circuits, (branch wires 9,) instead of in the commonor return wire,g, there are many advantages derived from usingmechanical generators of electricity instead of batteries; and theinvention consists, partly, in the employment of a magnetoelectricgenerator at each station instead of a battery common to all thestations. A suitable generator for this purpose is represented in Fig.1, the same consisting of a permanent magnet, at, having a suitablearmature in its field, the axis a of said armature being shown assquared to receive a key for turning it, and having connected with it anactuating-spring, b, which revolves the armature after it has beenturned by the key to strain the spring.

The armature may be of the kind commonly known as the Siemens armature,having an H shaped core upon which the wire is wound and being connectedby suitable commutator brushes or springs with the wires 9'. By using amagnetogenerator of this kind a connection of low resistance ismaintained through the armature at each station between the wires 9 9,so that even if a battery were interposed in a cross-connection such asrepresented at g" the greater portion of its current would pass throughthe circuit, including the generator at station 3, and, unless a verylarge battery were employed, the magnet 6 would not receive sufficientcurrent to cause it to release the motor (1.

When my improved arrangement of circuits and generators is employed inconnection with the transmitter such as shown in Fig. 2, the record maybe made on a traveling strip, at, as follows, although the specificmeans for making the record that will now be described form no part ofthe present invention:

The strip m, on which the record is made, is fed forward with a uniformtime movement by a drum or wheel, m, which is connected with aclock-work, (not shown,) and the surface of the said strip is marked orindented by a point or stylus, it, connected with the armature-lever ofthe magnetic, one terminal of which is connected by wire It with theframework of the transn1itter,and thus with the arm f,and the otherterminal of which is connected by wire 70 with a metal ring, a,supported in the insulatingringf, and thus insulated from the frameworkof the transmitter. The said ring f contains one or more studs, 0, (seeFig. 5,) preferably placed midway between the ad jacent pairs ofstation-studs f so that the finger f will make contact with the saidstuds 0 as it passes from one to the next of the station-studs f Thestuds 0 are in metallic connection with pieces 0, extending beneathscrews o",that pass through the ring a, so that by turning down any oneof the said screws 0 the corresponding stud 0 will be placed inelectrical connection with the ring a and wire it, and consequently whenthe arm f passes the said stud '0 the circuit k is will be closed andthe recording-magnet 7c energized and a record made. Thus one or anydesired number of marks may be recorded at each revolution of the armfproduced by a round of visits of the watchman at the stations; but itis obvious that the arrangement of the generator of electricity in thebranch or station wires instead of in the common return-wire isapplicable to various forms of receiving and recording mechanism, andthe invention is not limited to an apparatus containing a transmittingand recording mechanism such as herein shown.

I claim-- 1. In a watchmans time-detector apparatus, a series of branchcircuits leading from a receiving-station to different stations to bevisited and a return-wire common to several of said stations, combinedwith a generator of electricity connectedin circuit with the branch wireat the station to be visited and a receiving-instrument having a switchor circuitchanger by which the said branch circuits are connected one ata time successively with the said receivinginstrument, substantially asdescribed.

2. A watchmans detector apparatus comprising a magneto-generatorconsisting of a movable armature and field-magnet at each station, acircuit connecting said station with a receiving-station, and receivingapparatus comprising recording mechanism, the operation of which iscontrolled by the currents I 5 generated at the stations, and acircuit-changer that connects the said branch circuits one at a timesuccessively with the receiving apparatus, substantially as described.

In testimony whereof I hereto affix my signa- 2o ture in presence of twowitnesses.

- GEO. B. FESSENDEN.

Witnesses:

A. H. SPENCER, E. A. PHELPS.

